JPS6353758A - Motor controller - Google Patents

Abstract

PURPOSE:To attain the stable synchronizing control of the rotation of a motor for external synchronizing signals with a wide range of frequencies, by changing the state of a frequency voltage conversion means by an output which detects the frequency of the external synchronizing signal that becomes the reference of the rotating phase of the motor. CONSTITUTION:A frequency detection circuit 14 is constituted of a horizontal synchronizing signal separation circuit 12, a timepiece measuring circuit 13, and a flip-flop circuit 21. A horizontal synchronizing signal component is separated out of the external synchronizing signal outputted from an external synchronizing signal generating device 1, and the frequency of the external synchronizing signal is detected, and the state of an F-V conversion circuit 9 is changed by its output. In this way, since the rotation of the motor can be stably synchronized with the synchronizing signal even whose frequency is dislocated from the frequency stipulated by a standard system, it is possible to stably record and reproduce a video signal having such synchronizing signal on a disk.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention records information on a disc-shaped recording medium (disc) used in a video disc, etc. The present invention relates to a motor control device mainly used in recording and reproducing devices that read out.

(Conventional technology) A device that records and plays information using laser light.

(1) It is non-contact and has a long media life. (2) It is high density. (3) It is capable of high-speed random access. Recently, many business-use devices that can record and reproduce document files, image files, data files, files, etc. have been announced.

An example of a conventional motor control device used in the above-described device will be described below with reference to the drawings.

FIG. 7 is a block diagram showing a conventional example of a motor control device used in a device for recording and reproducing information on a disk.

In FIG. 7, 5 is a frequency generator attached to the motor 3. From frequency generator 5.

A signal with a frequency proportional to the rotation speed of the motor 3 is output. Reference numeral 9 denotes an F-V conversion circuit, which converts the frequency signal output from the frequency generator 5 into a voltage signal. A speed comparator 8 compares the voltage signal output from the F-V conversion circuit 9 with the voltage output from the reference voltage generation circuit 20 to detect a rotational speed error of the motor 3. Reference numeral 4 denotes a rotation pulse detection circuit, which is composed of a light emitting diode and a light receiving element, detects a synchronization mark provided on the disk 2 attached to the motor 3, and outputs a pulse-like signal. Reference numeral 1 denotes a synchronization signal generator provided externally. 10 is a phase comparator,
The phase difference between the synchronization signal output from the external synchronization signal generator 1 and the pulse signal output from the rotation pulse detection circuit 4 is detected, and the phase difference is converted into a voltage value and output.

The output of the speed comparator 8 and the output of the phase comparator 10 are as follows.

Added by adder 7. The output signal of this adder 7 is output to a motor drive circuit 6 to control the motor 3.

In the above conventional example, in order to rotate the motor 3 in synchronization with an external synchronization signal input from the outside, the external synchronization signal frequency is selected to be an integral multiple of the motor's rotation speed per second.

Further, in the conventional example, since the sensitivity of the F-V conversion circuit 9 and the reference voltage of the speed comparator 8 are fixed, the external synchronization signal that can synchronize the rotation with the motor is limited to a narrow range.

(Problems to be Solved by the Invention) Such a conventional configuration has a problem in that the types of external synchronization signals, the models of external synchronization signal generators, etc. are limited to a narrow range.

The present invention has been made in view of these problems, and an object of the present invention is to construct a motor control device that can stably control the rotation of a motor in synchronization with an external synchronization signal having a relatively wide range of frequencies.

(Means for Solving the Problems) In order to solve the above problems, the present invention detects the frequency of a synchronizing signal input from the outside, detects the rotational speed of the motor based on the detection signal, and detects the rotation speed of the motor based on the detection signal. The configuration is such that the state of the F-V conversion circuit and the state of the speed comparator provided in the system for controlling the rotational speed of the motor are changed.

(Function) With the above-described configuration, the present invention can stably rotate the motor with respect to the external synchronization signal even when a synchronization signal whose frequency deviates from the frequency determined by the standard system is input from the outside. Since synchronization is possible, it is possible to easily configure a system that can record and reproduce video signals having a synchronization signal as described above.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of a motor control device of the present invention. In FIG. 1 and FIG. 7, the same components are given the same numbers.

In FIG. 1, 12 is a horizontal synchronizing signal separation circuit.

This is composed of a monomulti, etc., and separates the horizontal synchronization signal component from the external synchronization signal output from the external synchronization signal generator 1. The time measurement circuit 13 is composed of a crystal oscillator or the like, and is turned on and off by the output of the flip-flop circuit 21. The flip-flop circuit 21 and the time measuring circuit 13 measure the time for one cycle of the horizontal synchronizing signal.

The horizontal synchronization signal separation circuit 12 and the time measurement circuit 13
and the frequency detection circuit 1 by the flip-flop circuit 21
4. 9 is an F-V conversion circuit.

The operation of the F-V conversion circuit 9 will be explained using FIG. 2. F
-V conversion circuit 9 converts the signal output from frequency generator 5 [
2(B)] to create a triangular wave as shown in FIG. 2(A), and the value V, □ just before the triangular wave is reset at the rising edge e of the signal in FIG. 2(B). This circuit holds and sends it to the speed comparator 8.

The number of revolutions per second of the motor 3 is R1, and the number of pulses output from the frequency generator 5 every time the motor 3 rotates once is Z.
Then, the T-work shown in Fig. 2 is T1=1/(R1
−Z).

When the reference voltage value provided in the speed comparator 8 is equal to v1□ shown in FIG. 2, the speed of the motor 3 is controlled so that it rotates at a rotation speed of R/sec.

As described above, when the frequency of the externally input synchronizing signal changes, the rotational speed of the motor 3 must be changed in order to synchronize the rotation of the motor with the external synchronizing signal.

Let R2 be the rotational speed of the motor 3 when the motor is rotated in phase synchronization with an external synchronization signal having a different frequency, and if, for example, R2<R1 is selected, then the triangular wave created by the F-V conversion circuit 9 is The result will be as shown in Figure 3 (A, ). At this time, T2 in FIG. 3 is T2=1/(R2·Z). As mentioned above, the voltage value output to the speed comparator circuit 8 at this time is Vyo□, and as shown in FIG.
> v-1, the motor 3 cannot continue to rotate at this rotation speed.

Therefore, in the above case, the slope of the triangular wave created by the F-V conversion circuit 9 may be changed as shown in FIG. 3(C). If you change it like this, the speed comparator 8
The voltage value output to is equal to the above V and □, and the motor 3 can continue to rotate stably at the rotation speed of R2.

From the above, if the frequency of the external synchronization signal is detected by the frequency detection circuit 14 and the state of the F-V conversion circuit 9 is changed as described above based on the output, the motor can be stably controlled against a wide range of external synchronization signals. can be rotated synchronously.

Also, when the frequency of the external synchronization signal changes as described above, the reference voltage value provided in the speed comparator 8 is changed from the above v to V.
Even if the frequency is changed to 12, the motor 3 can rotate stably in synchronization with the synchronization signal frequency.

In the above embodiment, an example was shown in which the frequency change of the synchronization signal in the video signal inputted from the outside is detected using the horizontal synchronization signal among the synchronization signals. It is also possible to detect

In the above embodiment, the frequency generator 5 is used as a device for detecting the rotational speed, but it can also be easily realized using an optical encoder or a tachogenerator. Also, as a means of detecting the rotation angle of the disk attached to the motor,
Although the embodiment described above uses a synchronization mark provided on the disk, the rotation angle of the disk may also be detected using a synchronization signal or a number signal recorded on the disk.

FIG. 4 shows another embodiment of the present invention in which the F-V conversion circuit 19 is configured using a clock signal generation circuit 16 that generates a clock signal, a counter 17 whose count setting is variable, and a low-pass filter 18. It is something. Note that the same parts as in FIG. 1 are given the same numbers and their explanations will be omitted.

The operation of the F-V conversion circuit 19 will be explained using FIG. 5.

FIG. 5(A) shows the output of the frequency generator 5, and the above-mentioned first
As described in the embodiment, if the number of revolutions per second of the motor 3 is R3, then T,=1/(R,·Z). Fifth
FIG. 5(B) shows a clock signal with a period TG outputted from the clock signal generation circuit 16 [shown in FIG. 5(C)] by a counter 17, m clock signals (shown in FIG. 5(C)) from the rising edge e of the signal in FIG. In the example shown in FIG. 5, these are signals created by counting 5 signals. This signal in FIG. 5(B) is transmitted through the low-pass filter 18.
is output to. This signal is converted into a voltage signal by the low pass filter 18. At this time, the speed comparator 8 has
Let k be the constant of proportionality.

A voltage signal of V, ,=k(1-<) is output.

At this time, the reference voltage value provided inside the speed comparator 8 is 7 g.
3, the motor 3 can continue to rotate stably at the rotation speed R1. As shown in the first conventional example above, when the frequency of the synchronization signal input from the outside changes, it is necessary to change the rotation speed of the motor 3 in order to synchronize the external synchronization signal and the rotation of the motor. becomes. motor 3
When the motor 3 is rotated in phase synchronization with the external synchronization signal having a different frequency, the rotational speed of the motor 3 is set to R4. For convenience of explanation, it is assumed that R4<R3. If the number of revolutions per second of the motor 3 is R4, the voltage value v,4 output from the low-pass filter 18 is as follows: V,4=k (1-1).

-R4 On the other hand, since R*<R3, V, 4<V, .
The motor 3 cannot continue to rotate at the rotation speed of R4.

Therefore, in the above case, the count number of the counter 17 provided in the F-V conversion circuit 19 may be changed. This will be explained below using FIG. 6.

Figure 6(A) shows the signal output from the frequency generator when the motor rotation speed per second is R4, T, = 1/
(R4・Z). In FIG. 6(B), the clock output from the clock signal generation circuit 16 is counted by the counter 17, m times (sixth edge) from the rising edge e of the signal in FIG.
This is a signal created by counting 10 signals (in the figure). As shown in FIG.
As is clear from the comparison, the voltage value V□ output to the terminal 8 is T, /T, = T, /T.

It is. Therefore, V,3=V,5, and the motor 3 can continue to rotate stably at the rotation speed R4.

As described above, in this embodiment, by varying the count setting number of the counter 17 in the F-V conversion circuit by the output of the frequency detection circuit 14, even when the external synchronization signal changes, the synchronization signal is It was shown that the rotation of the motor could be stably synchronized.

By the way, when the S/N of the external synchronization signal is poor, the frequency detection circuit 14 may erroneously detect the frequency of the external synchronization signal, and the rotation of the motor 3 may become unstable. Therefore, in order to prevent this kind of thing, the above F-
To change the states of the V conversion circuit 19 and speed comparator 8,
It is sufficient to do this only once, immediately after power is supplied to the present motor device, or when a command to start the motor 3 is output from a command device provided in the recording/reproducing device.

In addition, in order to cope with the case where the external synchronization signal frequency changes while the motor 3 is rotating, a circuit is provided in this motor control device to detect synchronization disturbance between the motor rotation and the external synchronization signal. The state of the F-V conversion circuit 19 or the speed comparator 8 may be changed when a synchronization disturbance between the rotation and the external synchronization signal is detected.

(Effects of the Invention) As described above, according to the present invention, it is possible to stably synchronize the rotation of the motor even with a synchronization signal in which one frequency deviates from the frequency determined by the standard system.
Video signals having synchronization signals such as those described above can also be stably recorded and reproduced on a disc. Furthermore, the present invention can be widely applied not only to systems that record and reproduce information using disks, but also to systems that have a function of recording and reproducing information by synchronizing the rotation of a motor with an external synchronization signal, such as a VTR. The effect is great because it can be done.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a motor control device in an embodiment of the present invention, FIG. 2 is a waveform diagram of main parts of an F-V conversion circuit,
FIG. 3 is a waveform diagram of the main parts of the F-V conversion circuit, FIG. 4 is a motor control device in another embodiment of the present invention, and FIG. 5 is a diagram of the F-V conversion circuit.
FIG. 6 is a waveform diagram of the main part of the conversion circuit, FIG. 6 is a waveform diagram of the main part of the F-V conversion circuit, and FIG. 7 is a block diagram of a conventional motor control device. 1... External synchronization signal generator, 2... Disk,
3...Motor, 4...Rotation pulse detection circuit,
5... Frequency generator, 6... Drive circuit, 7.
...Adder, 8...Speed comparator, 9.19...F
-V conversion circuit, 10... phase comparator, 11...
Vertical synchronization signal separation circuit, 12... Horizontal synchronization signal separation circuit, 13... Time measurement circuit, 14... Frequency detection circuit, 21... Flip-flop circuit. Patent applicant Matsushita Electric Industrial Co., Ltd. Figure 2 Figure 3 Figure 5 Figure 6 Section

Claims (9)

[Claims] (1) A rotational speed detection means that outputs a signal with a frequency proportional to the rotational speed of the motor, a frequency-voltage conversion means that converts the output of the rotational speed detection means into a voltage value, and the converted voltage value and a reference voltage. speed comparison means for comparing the values and outputting an error signal thereof; rotation angle detection means for detecting a synchronization mark provided on a disk attached to the motor so as to detect the rotation angle of the disk; a phase comparison means that compares an external synchronization signal serving as a reference for the rotational phase of the motor with the output of the rotation angle detection means and outputs an error signal; and an output of the speed comparison means and an output of the phase comparison means. A motor drive means for controlling the motor in phase synchronization at a predetermined rotation speed, and a frequency detection means for detecting the frequency of an external synchronization signal serving as a reference for the rotational phase of the motor, and the frequency is determined by the output of the frequency detection means. A motor control device characterized by changing the state of voltage conversion means. (2) The motor control device according to claim (1), wherein the rotation angle of the disk is detected based on a synchronization signal recorded on the disk. (3) In order to indicate the position of the information recording/reproducing track on the disk, the rotation angle of the disk is detected based on an address signal provided in the information recording/reproducing track. A motor control device according to claim (1). (4) The frequency-voltage conversion means is constituted by a triangular wave generating circuit or a trapezoidal wave generating circuit that generates a triangular wave or a trapezoidal wave whose slope changes continuously according to a control signal, and the triangular wave generating circuit or the trapezoidal wave generating circuit The motor control device according to any one of claims (1), (2), and (3), wherein: is controlled by the output of the frequency detection means. (5) The frequency-voltage conversion means is composed of a clock signal generation circuit that generates a clock signal and a counter circuit whose count number changes according to a control signal, and the count number of the counter means is controlled by the output of the frequency detection means. The motor control device according to any one of claims (1), (2), and (3). (6) A reference voltage value provided in the speed comparison means is changed according to the output of the frequency detection means. The motor control device according to any one of item 3). (7) Immediately after power is supplied to the motor control device, the state of the frequency-voltage conversion means or the speed comparison means is changed. ), (3), (4), (5), or (6). (8) comprising a synchronization disturbance detection device for detecting a disturbance in synchronization between the rotation of the motor and the external synchronization signal, when the synchronization disturbance detection device detects a synchronization disturbance between the motor and the external synchronization signal; Claims (1), (2), (3), (4), and (4) of the claims are characterized in that the state of the frequency-voltage conversion means or the speed comparison means is changed. The motor control device according to any one of (5), (6), and (7). (9) The state of the frequency-voltage conversion means or the speed comparison means is changed when a command to start the motor is input from a command device in a recording/reproducing device. Any one of Section 1), Section (2), Section (3), Section (4), Section (5), Section (6), Section (7), or Section (8). The motor control device described in .